Modulator‐Controlled Synthesis of Microporous STA‐26, an Interpenetrated 8,3‐Connected Zirconium MOF with thethe‐iTopology, and its Reversible Lattice Shift

Abstract

A fully interpenetrated 8,3-connected zirconium MOF with the the-i topology type, STA-26 (St Andrews porous material-26), has been prepared using the 4,4',4"-(2,4,6-trimethylbenzene-1,3,5-triyl)tribenzoate (TMTB) tritopic linker with formic acid as a modulating agent. In the as-prepared form STA-26 possesses Im3‾ m symmetry compared with the Pm3‾ m symmetry of the non-interpenetrated analogue, NU-1200, prepared using benzoic acid as a modulator. Upon removal of residual solvent there is a shift between the interpenetrating lattices and a resultant symmetry change to Cmcm which is fully reversible. This is observed by X-ray diffraction and C MAS NMR is also found to be remarkably sensitive to the structural transition. Furthermore, heating STA-26(Zr) in vacuum dehydroxylates the Zr nodes leaving coordinatively unsaturated Zr sites, as shown by IR spectroscopy using CO and CD CN as probe molecules. Nitrogen adsorption at 77 K together with grand canonical Monte Carlo simulations confirms a microporous, fully interpenetrated, structure with pore volume 0.53 cm g while CO adsorption at 196 K reaches 300 cm STP g at 1 bar. While the pore volume is smaller than that of its non-interpenetrated mesoporous analogue, interpenetration makes the structure more stable to moisture adsorption and introduces shape selectivity in adsorption.

A Bifunctional MOF Catalyst Containing Metal–Phosphine and Lewis Acidic Active Sites

“…N,N-Dimethylformamide (DMF) was purchased from Acros Organics, 5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin (TCPP) from Frontier Scientific, and acetone from Fisher Scientific. Azobenzenedicarboxylic acid (ABDC), [19] 4,4',4''-(1,3,5-triazine-2,4,6triyl)tribenzoic acid (TATB), [20,21] and 4,4',4''-(2,4,6-trimethylbenzene-1,3,5-triyl)tribenzoic acid (TMTB), [22,23] were synthesised in the lab. Room temperature studies refers to temperature range from 15-25 8C.…”

New Microporous Lanthanide Organic Frameworks. Synthesis, Structure, Luminescence, Sorption, and Catalytic Acylation of 2-Naphthol

“…MTBA possesses intrinsic fluorescence. Even though a number of complexes with MTBA as a linker have been documented in the literature [28,30,31,[37][38][39][40][41], lanthanide(III)-based MOFs with this tritopic ligand have not been reported as yet.…”

Tuning the supramolecular isomerism of MOF-74 by controlling the synthesis conditions

“…They are usually monocarboxylic acids (e.g. formic, [16][17][18] acetic, 16,[18][19][20] benzoic 17,21,22 acids as well as aminoacids 23,24 ) which act as competitive coordination agents, regulating the pore size and the morphology of the crystals.…”